Showing papers on "Voltage droop published in 1987"

Pulse drive circuit

Abstract: In order to drive a capacitance load at a high speed without an undesirably large increase in the circuit size, a driving arrangement is provided to charge the capacitance load in accordance with a limited voltage. A voltage limiter is coupled to a supply voltage providing a predetermined limited voltage. A pulse generator is coupled to receive the limited voltage and to provide output pulses which are, in turn, limited in accordance with the output voltage of the voltage limiter. A driver is coupled between the supply voltage and the capacitance load, and is controlled by the output pulses of the pulse generator. In this way, the capacitance load is charged through the driver in accordance with the limited voltage. Since the voltage limiter is not arranged along a series connection between the driver and the capacitance load, the internal equivalent resistance of the voltage limiter does not detrimentally influence the resistance along the series connection.

Power-On-Reset (POR) circuit

Abstract: A Power-On-Reset (POR) Circuit compares a logic supply voltage to a reference voltage and provides a logic voltage validity signal if the logic voltage is greater than the reference voltage; the circuit delays, on startup, the validity signal for a selected period and then provides a drive signal for driving a solid-state switch which provides an open circuit on the presence of the drive signal, indicating logic voltage validity, and a short circuit in its absence, indicating invalidity; and the circuit immediately disables the drive signal if the logic voltage falls below the reference voltage. The selected start-up delay period is independent of the supply voltage magnitude.

Clocked CMOS bus precharge circuit having level sensing

Abstract: A circuit for charging a capacitive load such as a data or address bus in a VLSI circuit includes a voltage source input, a PFET switch connected between the voltage source input and the capacitive load or bus, and a voltage regulator connected to the capacitive load and to the gate of the PFET switch to cause the switch to conduct during a predetermined time only if the voltage on the capacitive load is less than a predetermined voltage, and to disconnect the capacitive load from the voltage source input when the voltage on the capacitive load reaches or exceeds that predetermined voltage level. The voltage regulator may include a first inverter having its input connected to the bus and a second inverter having an input connected to the output of the first inverter and having an output connected to the control input of the switch. The first inverter is constructed to output a low level when the voltage on the first inverter input is at or above the designated predetermined voltage. The predetermined voltage level is determined by the "trigger point" of the first inverter.

Regulated battery charger

Abstract: The present invention is an electrical circuit for regulating the average current through and the voltage across a load, such as a rechargeable battery. The circuit includes at least one semiconductor switching device connected in series with the load for controlling the current through the load. A current control loop is provided in the circuit to maintain the average current through the load at a constant level despite changes in the resistance of the load. Also provided is a voltage control loop which acts to limit the voltage across the load to a value below a predetermined voltage level.

Fast voltage reference stabilization circuit

Abstract: A circuit for providing a fast stabilization of the reference voltage level produced by a reference generation circuit includes a clamping circuit which clamps the refernece node at a voltage approximately equal to the voltage produced by the reference generation circuit when the reference voltage level is disabled. When the reference generation circuit is enabled, the reference node has to be pulled only slightly to reach the proper reference voltage, thereby increasing the speed of the device and the clamping circuit is turned off.

Method and an apparatus for boosting battery

Abstract: When boosting a battery, a direct current boosting voltage is applied between the positive and negative terminals of the battery via a pair of cables of predetermined length. In order to supply a boosting voltage of predetermined constant value, a direct current voltage source supplies the boosting voltage to the battery not only through the pair of the cables, but also through a high current adjustable load. Of course, the direct current voltage source supplies a voltage of value higher than the boosting voltage predetermined value. A voltage controller detects the voltage between the ends of the two cables adjacent to the voltage source, and the voltage drop in the pair of cables, and varies the high current adjustable load in response to the detected voltage and voltage drop so as to adjust the boosting voltage at the predetermined constant value.

Voltage regulation relay

Abstract: PURPOSE: To stably supply the voltage of a power system by comparing an average value of all the average values of voltages, each at each of a plurality of ground points of the system with a set voltage, and controlling the tap switching of an on-load tap changing transformer by the compared result. CONSTITUTION: The end voltages of the loads 3a, 3b in a power system are input to an input converter 12, and digitally converted voltages are input to a voltage regulating relay 13. The relay 13 calculates a time average voltage within a predetermined time for each input load terminal voltage, and then calculates an average value (whole average voltage) of all the time average voltages. The obtained whole average voltage is compared with a preset voltage, and if the whole average voltage is larger than the set voltage, a down command for executing the tap change for reducing the voltage with respect to an on-load tap changing transformer 9 is output, while if the while average voltage is lower than the set voltage, a rise command signal is output. COPYRIGHT: (C)1988,JPO&Japio

Gated base‐line restorer without ‘‘droop’’

Abstract: Different configurations of an analog gated base‐line restorer circuit are discussed. An elimination of a ‘‘droop’’ rate is achieved by replacing the analog memory by a digital one. A design employing a digital feedback loop is described.

Voltage translator with restricted output voltage swing

Abstract: A voltage translator containing a bipolar transistor (Q1), a rectifier (10), a resistor (R1), and a first clamp (12) converts an input voltage (VI) into one or more output voltages of restricted voltage swing. The first clamp clamps the emitter voltage of the transistor when it is turned on. In one version, the translator includes a second clamp (14) that clamps the collector voltage of the translator when it is turned off. The translator then provides an output voltage (VO) inverse to the input voltage. In another version, the first clamp is connected between a voltage supply (VEE) and the emitter of the transistor. Its collector is connected directly to another voltage supply (VCC) so that the translator only makes non-inverting translations.

Voltage shock protection circuit

Abstract: A voltage shock protection circuit having two anti series connected field effect transistors adapted for being connected between a conductor and a protected circuit for connecting the protected circuit to the conductor and also protecting the protected circuit against voltage transients possibly occurring in the conductor, the voltage transients having excessively high or low potentials that could damage the protected circuit. The voltage shock protection circuit has a voltage sensing circuit connected to the protected circuit and to the conductor so that it is sensitive to voltage drops across each of the anti series connected field effect transistors and adapted such that when either of the voltage drops becomes sufficiently great one of the field effect transistors is pinched off. The voltage sensing circuit may include a field effect transistor. The two anti series connected field effect transistors and/or the field effect transistor in the voltage sensing circuit are dimensioned such that in their conductive state they become saturated on the occurrence of a voltage transient with a damaging potential.

Source bias generator for natural transistors in MOS digital integrated circuits

Abstract: The bias voltage generator is particularly intended for EPROM memory address decoder circuits, and comprises: (a) a stage generating a reference voltage approximately equal to the turn off threshold voltage of a natural transistor, with its sign changed; and (b) a doubler stage driven by the reference voltage and adapted to supply a bias voltage equal to twice the turn off threshold voltage with its sign changed. Preferably, the bias voltage generator furthermore comprises an adjustment stage driven by the output bias voltage to inject an additional current in negative feedback into said doubler stage when the output bias voltage drops, to return it to the desired value.

Sense circuit of a semiconductor memory device

Abstract: A sense circuit of a semiconductor memory transistor includes a bit line connected to a memory cell which stores "1" or "0". The sense circuit includes a MOS transistor which has its gate connected to the bit line, its source connected to ground voltage and its drain connected to a supply voltage through a load MOS transistor. The sense circuit also includes a compensating circuit for compensating the voltage at the bit line when the ground voltage has fluctuated. For example, the compensating circuit includes a pull-up circuit for pulling up the voltage at the bit line when the ground voltage has shifted to the positive side and a pull-down circuit for pulling down the voltage at the bit line when the ground voltage has shifted to the negative side, thereby maintaining the relative voltage relationship between the voltage at the bit line and the ground voltage at a proper value.

Fluid conductivity sensor for actuating an electroexploding device

Abstract: Apparatus for sensing the electrical conductivity of fluid wherein when electrodes of the apparatus are exposed to fluid a voltage is developed on a capacitor which voltage has a magnitude determined by the condition of the electrical conductivity of the fluid to which the electrodes are exposed. A portion of the developed voltage is obtained, such as by means of a voltage divider connected across the capacitor, and this voltage portion is compared by means of a voltage comparator to a reference voltage. When the comparison indicates a predetermined relationship, for example equality, between the developed voltage portion and the reference voltage, a signal is produced which can be utilized to operate a load. In particular, the signal can operate a semiconductor controlled rectifier to complete a discharge path from the capacitor to the load. The load can be an electro explosive device included in a release mechanism for uncoupling a parachute canopy from its load upon landing in water. The load is connected in a series loop including the electrodes, voltage divider and a voltage source with the result that the electrical integrity of the load can be tested using standard equipment and procedures.

Integrable buffer circuit for voltage level conversion having clamping means

Abstract: A signal voltage (E) based upon a supply voltage must be converted to a signal voltage (A) with ground reference so as to enable further processing in a logic circuit. A simple level converter comprises a series connection of a MOSFET (T1) connected to the supply voltage; the MOSFET also comprises a resistor (T2). The source terminal of the MOSFET (T1) is located at the potential of the supply voltage. The voltage to be converted is applied between the gate terminal and the source terminal, and the converted voltage occurs at the resistor (T2). The two voltages are each limited by one Zener diode (D2, D1).

Supply circuit for supplying a smoothed direct current to a load impedance

Abstract: A supply circuit comprising an FET as a series element in series with the load resistance. The supply circuit is fed from the mains network via a rectifier 54 and a smoother 52, causing a ripple voltage to be present on the input terminals 2-1 and 2-2. The direct voltage component of the input voltage is present across load resistance 60, the alternating voltage component of this voltage being present across transistor 10. With known supply voltage circuits the voltage drop across the series element is selected to be equal to the maximum peak-to-peak value of the alternating voltage component, causing unnecessary dissipation to be developed at a minor ripple amplitude. This will cause fast ageing of the series element. The supply circuit in accordance with the invention comprises a comparator 42 comparing the voltage across transistor 10 to a threshold voltage. Comparator 42 controls the charge on the filter capacitors 30 and 32. Consequently, the overall voltage across transistor 10 will never exceed the sum of the threshold voltage and the peak-to-peak voltage of the voltage component of the input voltage.

DC voltage converter

Abstract: A DC voltage converter comprising: a switching transistor for establishing a load current circuit which connects a DC power source to a load to supply a load current to the load; a differentiating circuit connected in series to the load current circuit for producing a voltage drop corresponding to a differentiated value of the load current; an integrating capacitor connected in parallel with the load via an output terminal for outputting as an output voltage to be supplied to the load a voltage corresponding to an integrated value of a current flowing through the capacitor; a control width setting circuit for setting a width defined by upper and lower limits for controlling the output voltage in accordance with the voltage drop derived from the differentiating circuit; a ripple detection circuit receiving the output voltage from the capacitor and for detecting a ripple caused by an "ON-OFF" operation of the switching transistor; an output-reference-level setting circuit for setting a reference voltage of the output voltage; and a switching control circuit receiving a width signal corresponding to the width and a ripple signal corresponding to the ripple for forming a switching instruction to the switching transistor, so that a variation in the output voltage is limited within the width.

Switching power source device

Abstract: PURPOSE: To contrive the energy saving of electric power, by a method wherein switching operation is controlled by setting and switching the value of a voltage, outputted to a load, so that it is changed from a rated voltage to a low voltage sequentially while detecting the operating condition of the load. CONSTITUTION: An electronic computer system, employing a switching power source device, is constituted of a CPU 1, a clock oscillator 2, a logical operation circuit unit 3, a memory 4, a power source device 5, control wires 12, 13 and the like. The value of a voltage, outputted to a load, is set and switched so that it is changed from a rated voltage, for example, to a low voltage sequentially while detecting the operating condition of the load by a voltage setting and switching means. The value of the set voltage is compared with the value of the voltage, outputted to the load, and switching operation is controlled by a control means so that the value of outputted voltage becomes the value of the set voltage. According to this method, the voltage, outputted to the load, is controlled so as to become the lowest voltage which can operate the load normally whereby the energy saving of electric power may be contrived. COPYRIGHT: (C)1989,JPO&Japio

Circuit arrangement for a switched-mode power supply

Abstract: If a switched-mode power supply is operated in the standby mode, that is to say on a low load, then its output voltage increases in comparison with the output voltage at a higher load. The filter capacitors which are required on the secondary side must therefore be designed for correspondingly high voltages and are thus expensive. In order to avoid this, it is proposed to reduce the regulation voltage at the regulation input of the drive circuit when the load is low. A switching device is described for this purpose, which reduces the regulation voltage as a function of the depletion voltage occurring in the switching transistor.

Method of and apparatus for controlling the braking resistor of a frequency converter

Abstract: A method of and apparatus for controlling a braking resistor, provided in a d.c. circuit of a frequency converter, by rectifying a mains voltage, by means of a first rectifier bridge connected to a three-phase mains supply, to form an actual value voltage; comparing said actual value voltage and a reference voltage; and operating a switch in series with the braking resistor to cause the latter to conduct when the comparison indicates that the actual value voltage is greater than the reference voltage. The reference voltage is formed from a rectified voltage obtained from the three-phase mains supply and rectified by a second rectifier bridge.

Voltage translator circuit

Abstract: A voltage translator circuit generates a predetermined output voltage (e.g. one half of the supply voltage) in response to a predetermined input voltage. A pair of matched field effect transistors are coupled in series between first and second sources of supply voltage. The gate of the load transistor is coupled to a reference voltage, and the gate of the drive transistor is coupled to a source of input voltage. When both transistors are subject to the same operating conditions (at a predetermined input voltage level), their effective resistances become equal and the supply voltage is divided in half. The circuit does not depend for its operation upon precise threshold voltages of the devices as long as the devices are matched.

On-vehicle load power supplying circuit

Abstract: PURPOSE:To perform a completion of an icing prevention in a short time by composing to generate a high voltage even if the rotating speed of an alternator is limited. CONSTITUTION:When an icing preventive switch 19-1 is closed, a signal for turning OFF a transistor 4-3 for a short period is output from a controller 19 to set the current of a rotor coil 1-3 to 0. Thus, an alternator 1 stops generating during the period. Further, the controller 19 generates a signal for turning OFF a low voltage load relay 18 and a signal for turning ON a high voltage load relay 17. Thus, a voltage is supplied to a low voltage load 15 only from a battery 14, and a high voltage is supplied from the alternator 1 to a high voltage load 7 through a high voltage rectifier 3. Since a voltage application to a rotor coil 1-3 eliminate a regulation of a voltage regulator 4 because a rotor coil relay 4-10 is turned ON, the generating voltage of the alternator 1 is not limited.

Low‐noise ac/dc voltage source with continuous zero crossing

Abstract: We have developed an active voltage source with low‐noise characteristics. The circuit was designed to drive components at constant voltage which are sensitive to extrinsic noise and power‐supply zero‐crossing transients.

High voltage-generating circuit arrangement for the operation of a picture tube

Abstract: In a circuit arrangement for generating a high voltage for operation of a picture tube, the primary winding of a transformer via a semiconductor switch periodically voltage source with an operating chip is connected. The secondary winding is divided into several part windings which are interconnected via the Dio. A further diode forming the output of the high voltage. A derived from the high voltage control voltage is supplied to a regulator for keeping constant the high voltage, while the width of the driving pulses of the semiconductor switch or the operating voltage can be controlled.

Circuit arrangement for producing a high, stable DC voltage

Abstract: In order to stabilise the high voltage (high tension) in a television set, the switching time for an electronic switch is controlled by the control variable which is derived from the high voltage, which is produced with the aid of a high-voltage transformer. This electronic switch switches a transformed voltage, which is supplied by a secondary winding, to reference potential (reference earth) via a storage inductance. The magnetic energy, which may be more or less large, is transferred into the high-voltage circuit so that the high voltage is kept constant depending on the load on it.

Load distribution control apparatus of turbine generator

Abstract: PURPOSE:To enable a favorable balance to be secured between supply and demand of power, by making increasing and decreasing control according to load fluctuation by means of a general drooping characteristics arithmetic circuit and a ratio regulator mounted to a load distribution control apparatus of a generating plant consisting of plural number of turbine generators CONSTITUTION:In a load distribution control apparatus for controlling plural number of turbine generators 1-3, an adder 42 is connected to a general load setter 41, and also each ratio regulator 15 receiving the ratio of a load distributed to each of generators 1-3 after branching from the adder 42 is also connected thereto Each ratio controller 15 is connected to a revolution setter 16 mounted to the governor of each of generators 1-3 and at the same time, outputs taken out from generator main circuits 51-53 are fed back to the respective ratio controllers 15 through LPF 17 of output Moreover, by providing a circuit for detecting frequencies accompanying the load fluctuation of power system from a transmission line 54, the set value of the total load is automatically corrected by the general droop characteristic arithmetic circuit 43 based on the deviation amount thereof so that it may be output to the adder 42

Output stage of an integrated semiconductor circuit

Abstract: In conventional output stages, parasitic diodes are unavoidably formed by the variously doped regions High currents can flow via the diodes from a voltage supply source, with the result that the circuit is destroyed The intention is to provide a protection against such overvoltages An output stage of an integrated semiconductor circuit has: a signal generating circuit (20), a first voltage generating device (70) for feeding a voltage which is higher than the voltage of a high-potential voltage supply (1) to a back-gate electrode (9) of a P-channel FET (4) connected between the high-potential voltage supply (1) and a low-potential voltage supply (2) after the voltage supply device (70) has received the output of the signal generating circuit, a second voltage generating device (80) for feeding a voltage which is lower than the voltage of the low-potential voltage supply (2) to a back-gate electrode (16) of an N-channel FET (5) connected between the high-potential voltage supply (1) and the low-potential voltage supply (2) after the second voltage supply device (80) has received an output from the signal generating circuit (20) Consequently, a voltage which is higher than the voltage of the high-potential voltage supply (1) is Original abstract incomplete

Adjustable semi-digital voltage control circuit

Abstract: The previously exclusively fully analog voltage control circuits can be adjusted only inaccurately without a voltmeter. In addition, ergonomics and technical data require improvements. Digital methods are used for achieving a more accurate adjustment of the output voltage. This is provided by a 4-bit binary counter which is followed by a D/A converter and a potentiometer. The output voltage in each case increases by 1 V when the binary counter is incremented. 15 voltages (maximum deviation: 0.03 V) are available; intermediate values are set with the potentiometer. Because it is independent of the coarse adjustment, the fine adjustment becomes more accurate. The constant voltage which should be as stable as possible and is needed in the case of voltage control circuits is provided by a battery instead of the usual Z diodes. Since the battery is independent of input voltage fluctuations, it has ideal characteristics. The battery remains almost free of load by connecting to it a voltage follower. The output voltage of the voltage follower, which has a high load-carrying capability, is always identical with the battery voltage. In general, the use of voltage followers throughout contributes to an improvement of the technical data and the use of light-emitting displays contributes to improved ergonomics for reading the set output voltage. The circuit is suitable for installation in power supplies and for correcting the output voltage of power supplies.

Method for compensating voltage variations in a magneto-resistive bridge element

Abstract: In the method, the bridge output voltage is amplified by means of an operational amplifier. The technical problem is the provision of a method for compensating such voltage variations and for providing symmetrical output pulses with a constant sampling ratio. The output voltage of the bridge element is compared with the average value of the bridge output voltage and, whenever the bridge output voltage passes through the average value, the level of the output value of the comparison operation is reversed.